The invention relates to a color projection system comprising at least a light source, at least an integrator plate arranged in front of the light source and comprising a plurality of juxtaposed lens elements, an electro-optical light modulation panel arranged in front of the integrator plate, at least a projection lens preceding the light modulation panel, and a movable color filter which is provided with a plurality of parallel extending, differently colored strips.
In such a color projection system known from JP-A-4.54093 (Toshiba Corporation), the color filter precedes the light modulation panel. The color filter has at least three differently colored strips. The colors of the strips are red, blue and green. The color filter is moved in front of the light modulation panel while simultaneously a part of the image to be projected corresponding to the color of the color strip facing the relevant part is generated on each portion of the light modulation panel. By moving the color filter relatively quickly and simultaneously adapting the parts of the image to be projected, which parts are generated on the light modulation panel, the red, blue and green part of the image is generated on each part of the light modulation panel and projected through the oppositely located colored strip and the projection lens. By projecting the three different colors of an image rapidly one behind the other, a fully colored image is observed by the human eye.
It is an advantage of such a color projection system that only one light modulation panel needs to be used.
However, it is a drawback of such a color projection system that the color filter is located in the imaging portion so that the color filter must have a sufficient optical quality, while it must be moved relatively very accurately and must be mechanically stable so as to ensure a qualitatively satisfactory projected image. Moreover, each colored strip should be moved through a relatively large distance of the complete light modulation panel.